Metamaterials for microwaves and optics

Summary form only given. In the present talk we discuss our recent attempts to obtain artificial magnetic metamaterials (i.e. metamaterials of negative permeability) and left-hand-handed materials (i.e. metamaterials of both negative permeability and permittivity) in the optical regime by scaling down well established microwave metamaterial designs. We focus on designs based on pairs of slabs (giving negative permeability) and continuous wires (giving negative permittivity) and we examine the scaling behavior of those designs through examination of the magnetic and electric resonance frequencies and the permeability and permittivity resonances. The most pronounced observed characteristics are (a) the saturation of all the characteristic frequencies of the metamaterials in the optical regime and (b) the weakening of the magnetic permeability resonance. Those results are explained taking into account the kinetic energy of the electrons in the metallic components of the metamaterials. The consideration of the kinetic energy leads also to approximate analytical formulas for the saturation values of the characteristic frequencies, which are useful for the optimization of the metamaterials designs.